How to open a modal window for a custom datatype in the Umbraco back office

Opening a modal window in the back office of Umbraco, is easy using the example code below, just bare in mind that the modal window isn't like a bootstrap modal window in the sense that bootstrap opens its modal windows in a relatively square box on top of the content. Umbraco instead opens its modal windows as a content area on the right hand side of your screen.

Example Output:

Further reading:

Be aware that this will open a web address as if it were a proper modal window i.e. you could load http://www.google.co.uk/ into it and it would load just fine in the side bar. As such, any local file you open will need to be a complete .html file with all standard html tags as if it were a standalone page.

If you're looking to open it as a dialog window so that you can parse data to and from the page without having to declare all the html around it, you'll need to read up on the dialogService.